Metallisation

Abstract

This invention relates to photosensitive organometallic compounds which are used in the production of metal deposits. In particular, this invention relates to photosensitive organometallic compounds such as bis-(perfluoropropyl)-1,5-cyclooctadiene platinum (II) (i.e. (C 3 F 7 ) 2 PtC 8 H 12 ) which on exposure to UV radiation and then a reduction process forms a platinum metal deposit such as a substantially continuous thin ‘sheet-like’ film or a substantially narrow line which is capable of electrical conduction.

1. A method for forming metal deposits on a substrate comprising:
 a) depositing a photosensitive organometallic compound onto a substrate; 
 b) irradiating the photosensitive organometallic compound with UV radiation; 
 c) reducing the irradiated photosensitive organometallic compound to form metal deposits adhered to the substrate in a process which comprises:
 1) a first heating and cooling stage; 
 2) a second heating and cooling stage in an oxidizing atmosphere; 
 3) flowing an inert gas over the substrate; and 
 4) a third heating and cooling stage wherein a reducing gas flows over the substrate to form metal deposits; and 
 
 d) removing any degraded photosensitive organometallic compound residue and unaffected photosensitive organometallic compound from said substrate. 
 
   
   
     2. A method for forming metal deposits on a substrate according to  claim 1  wherein the first heating and cooling stage is in an inert atmosphere such as a noble gas. 
   
   
     3. A method for forming metal deposits on a substrate according to  claim 2  wherein the noble gas is dinitrogen. 
   
   
     4. A method of forming metal deposits on a substrate according to  claim 1  wherein the oxidizing atmosphere comprises a dioxygen containing atmosphere such as air. 
   
   
     5. A method of forming metal deposits on a substrate according to  claim 1  wherein the reducing gas in the third heating and cooling stage comprises at least dihydrogen. 
   
   
     6. A method for forming metal deposits on a substrate comprising:
 a) depositing a photosensitive organometallic compound corresponding to formula (I) as described below 
 
     
       
         
         
             
             
         
       
     
     wherein:
   M is a member of the group consisting of platinum, palladium, copper, rhodium, tungsten, iridium, silver, gold and tantalum;   A is any of oxygen, sulphur, an amide grouping, an amine grouping or an ester grouping;   x is 0 or 1;   R is a fluoroorgano group; and   L is a bidentate ligand;   
 b) irradiating the photosensitive organometallic compound with UV radiation; 
 c) reducing the irradiated photosensitive organometallic compound to form metal deposits adhered to the substrate; and 
 d) removing any degraded photosensitive organometallic compound residue and unaffected photosensitive organometallic compound from said substrate. 
 
   
   
     7. A method for forming metal deposits on a substrate comprising:
 a) depositing a photosensitive organometallic compound selected from the group consisting of: bis-(perfluoropropyl)-1,5-cyclooctadiene platinum (II); bis-(perfiuoropropyl)-1-methyl- 1,5-cyclooctadiene platinum (II); and bis-(perfluoropropyl)-1-fluoromethyl-1,5-cyclooctadiene platinum (II) onto a substrate; 
 b) irradiating the photosensitive organometallic compound with UV radiation; 
 c) reducing the irradiated photosensitive organometallic compound to form metal deposits adhered to the substrate; and 
 d) removing any degraded photosensitive organometallic compound residue and unaffected photosensitive organometallic compound from said substrate. 
 
   
   
     8. A method for forming metal deposits on a substrate comprising:
 a) depositing a photosensitive organometallic compound onto a substrate; 
 b) irradiating the photosensitive organometallic compound with UV radiation; 
 c) reducing the irradiated photosensitive organometallic compound to form metal deposits adhered to the substrate by a process comprising:
 (1) heating the coated substrate from about 25° C. to about 12° C. at a ramp rate of about 2° C. per minute; maintaining the temperature at about 80° C. for about 60 minutes; and then cooling the substrate from about 80° C. to about 25° C. at a ramp rate of about 10° C. per minute; wherein N 2  is flowed over the coated substrate at a rate of about 50 ml per minute; 
 (2) heating the substrate from about 25° C. to about 250° C. at a ramp rate of about 5° C. per minute; maintaining the temperature at about 250° C. for about 60 minutes; and then cooling the substrate from about 250° C. to about 25° C. at a ramp rate of about 5° C. per minute; wherein the coated substrate is exposed to air; 
 (3) flowing N 2  at about 25° C. over the coated substrate for about 10 minutes; and 
 (4) heating the coated substrate from about 25° C. to 25 about 350° C. for about 60 minutes; and then cooling the substrate from about 350° C. to about 25° C. at a rate of about 20° C. per minute; wherein a mixture of about 5% H 2  and 95% N 2  is flowed over the coated substrate at a rate of about 150 ml per minute; and 
 
 d) removing any degraded photosensitive organometallic compound residue and unaffected photosensitive organometallic compound from said substrate. 
 
   
   
     9. A method for forming metal deposits on a substrate comprising:
 a) depositing a photosensitive organometallic compound onto a substrate; 
 b) irradiating the photosensitive organometallic compound with UV radiation; 
 c) reducing the irradiated photosensitive organometallic compound to form metal deposits adhered to the substrate by a process comprising:
 1) heating the coated substrate from about 25° C. to about 120° C. at a ramp rate of about 2° C. per minute; maintaining the temperature at about 80° C. for about 60 minutes; and then cooling the substrate from about 80° C. to about 25° C. at a ramp rate of about 10° C. per minute; wherein N 2  is flowed over the coated substrate at a rate of about 50 ml per minute; 
 2) heating of the substrate from about 25° C. to about 350° C. at a ramp rate of about 20° C. per minute; maintaining the temperature at about 350° C. for about 60 minutes; and then cooling the substrate from about 350° C. to about 25° C. at a ramp rate of about 20° C. per minute; wherein the coated substrate is exposed to air; 
 3) flowing N 2  at about 25° C. over the coated substrate for about 10 minutes; and 
 4) heating the coated substrate from about 25° C. to about 350° C. at a ramp rate of about 20° C. per minute; maintaining the temperature at about 350° C. for about 60 minutes; and then cooling the substrate from about 350° C. to about 25° C. at a rate of about 20° C. per minute; wherein a mixture of about 5% H 2  and 95% N 2  is flowed over the coated substrate at a rate of about 150 ml per minute; and 
 
 d) removing any degraded photosensitive organometallic compound residue and unaffected photosensitive organometallic compound from said substrate.